Antenna-in-package structures with broadside and end-fire radiations

ABSTRACT

Package structures are provided having antenna-in-packages that are integrated with semiconductor RFIC (radio frequency integrated circuit) chips to form compact integrated radio/wireless communications systems that operate in the millimeter wave (mmWave) frequency range with radiation in broadside and end-fire directions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. patent application Ser. No.14/565,616, filed on Dec. 10, 2014, which is a Continuation-in-Part ofU.S. patent application Ser. No. 14/023,995, filed on Sep. 11, 2013, thedisclosures of which are fully incorporated herein by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

This invention was made with Government support under Contract No.FA8650-09-C-7924 (awarded by the Advanced Research Development Agency).The Government has certain rights in this invention.

TECHNICAL FIELD

The field generally relates to package structures with integratedantennas and, in particular, package structures havingantenna-in-packages integrated with semiconductor RFIC (radio frequencyintegrated circuit) chips to form compact integrated radio/wirelesscommunications systems that operate in the millimeter wave (mmWave)frequency range with radiation in broadside and end-fire directions.

BACKGROUND

There is an increasing demand for low-cost wireless communicationsystems that operate in the 60-GHz frequency band and which supportgigabit-per-second (Gbps) data rates. Typical applications that demandGbps data rates include, for example, wireless gigabit Ethernet andwireless uncompressed high-definition video applications. Thistechnology allows users to wirelessly link portable devices such aselectronic tablets and smartphones to computers, kiosks, high-definitiondisplays and projectors, for example, with data rates that are thousandsof times faster than standard Bluetooth or Wireless LAN protocols.Recent advances in CMOS and SiGe technologies have enabled single chipsolutions, making the 60-GHz technology more commercially attractive.However, for the 60-GHz market to flourish, not only are low-cost devicesolutions required, but also low-cost RFIC packages with integratedantennas.

SUMMARY

Embodiments of the invention include structures and methods forintegrally packaging antenna structures with semiconductor RFIC chips toform compact integrated radio/wireless communications systems thatoperate in the millimeter wave frequency range with radiation inbroadside and end-fire directions.

In one embodiment of the invention, a package structure includes anantenna package and an RFIC (radio frequency integrated circuit) chipmounted to antenna package. The antenna package includes a stackstructure, wherein stack structure includes a plurality of substratesand metallization layers comprising a first metallization layer formedon a first surface of a first substrate, and a second metallizationlayer formed on first surface of a second substrate. The firstmetallization layer includes a first planar antenna and a planarparasitic element disposed adjacent to the first planar antenna. Thesecond metallization layer includes a second planar antenna. The RFICchip is mounted to the second metallization layer of antenna package.The first antenna is connected to the RFIC chip by a first antenna feedline comprising a metalized via hole that is formed through the stackstructure, and wherein the second antenna is connected to the RFIC chipby a second antenna feed line that is formed as part of the secondmetallization layer. The first planar antenna is configured to receiveor transmit broadside signals and the second planar antenna isconfigured to receive or transmit end-fire signals. The planar parasiticelement is configured to reduce surface waves on the surface of thefirst substrate.

In another embodiment of the invention, an antenna package includes afirst substrate, a second substrate bonded to the first substrate usinga first adhesive layer, and a third substrate bonded to the secondsubstrate using a second adhesive layer. The first substrate includes afirst metallization layer disposed on a surface of the first substrate,wherein the first metallization layer comprises a first planar antennaand an ungrounded planar parasitic element disposed adjacent to thefirst planar antenna. The first planar antenna is configured to receiveor transmit broadside signals, and the ungrounded planar parasiticelement is configured to reduce surface waves on the surface of thefirst substrate. The second substrate includes a second metallizationlayer disposed on a surface of the second substrate, wherein the secondmetallization layer comprises a dedicated power plane to distribute DCpower supply voltage. The third substrate includes a third metallizationlayer formed on first surface of the third substrate and a fourthmetallization layer formed on a second surface of the third substrate.The third metallization layer comprises a dedicated ground plane. Thefourth metallization layer comprises a plurality of contact pads, one ormore antenna feed lines, and a second planar antenna, wherein the secondplanar antenna is configured to transmit or receive end-fire signals.The antenna package further includes a plurality of metalized via holesformed through the first, second and third substrates to provide one ormore antenna feed lines from contact pads of the fourth metallizationlayer to the first planar antenna. In addition, a plurality of metalizedvia holes are formed through the second and third substrates to provideconnections from contact pads of the fourth metallization layer to thepower plane of the second metallization layer, and a plurality ofmetalized via holes formed through the third substrate to provideconnections from contact pads of the fourth metallization layer to theground plane of the third metallization layer.

In yet another embodiment of the invention, an antenna package includesa first substrate, and a second substrate bonded to the first substrateusing an adhesive layer. The first substrate includes a firstmetallization layer disposed on a first surface of the first substrateand a second metallization layer disposed on a second surface of thefirst substrate. The first metallization layer includes a first planarantenna, a grounded planar parasitic element disposed adjacent to thefirst planar antenna, and a power supply patch. The first planar antennais configured to receive or transmit broadside signals. The groundedplanar parasitic element is configured to reduce surface waves on thesurface of the first substrate. The power supply patch is configured todistribute a DC power supply voltage. The second metallization layerincludes a capacitively coupled ground plane. The second substrateincludes a third metallization layer disposed on a first surface of thesecond substrate, wherein the third metallization layer comprises adedicated ground plane. The capacitively coupled ground plane is coupledto the dedicated ground plane through the adhesive layer. The secondsubstrate includes a fourth metallization layer formed on second surfaceof the second substrate, wherein the fourth metallization layer includesa plurality of contact pads, one or more antenna feed lines, and asecond planar antenna. The second planar antenna is configured totransmit or receive end-fire signals. The antenna package furtherincludes a plurality of metalized via holes formed through the first andsecond substrates to provide one or more antenna feed lines from contactpads of the fourth metallization layer to the first planar antenna, andto provide connections from contact pads of the fourth metallizationlayer to the power supply patch of the first metallization layer. Inaddition, a plurality of metalized via holes are formed through thefirst substrate to provide connections from the grounded planarparasitic element of the first metallization layer to the capacitivelycoupled ground plane of the second metallization layer, and a pluralityof metalized via holes are formed through the second substrate toprovide connections from contact pads of the fourth metallization layerto the ground plane of the third metallization layer.

These and other embodiments of invention will be described or becomeapparent from the following detailed description of embodiments, whichis to be read in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically depicts a wireless communications package accordingto an embodiment of the invention.

FIGS. 2A and 2B schematically depict an antenna package according to anembodiment of the invention.

FIGS. 3A and 3B schematically depict an antenna package according toanother embodiment of the invention.

FIG. 4 schematically depicts an antenna package according to anotherembodiment of the invention.

FIG. 5 schematically depicts an antenna package according to anotherembodiment of the invention.

FIGS. 6A and 6B schematically depict an antenna package according toanother embodiment of the invention.

FIGS. 7A and 7B schematically depict an antenna package according toanother embodiment of the invention.

FIGS. 8A and 8B schematically depict an antenna package according toanother embodiment of the invention.

FIG. 9 schematically depicts an antenna package according to anotherembodiment of the invention.

FIG. 10 schematically depicts a wireless communications packagestructure according to another embodiment of the invention.

FIG. 11 schematically depicts a stack structure of an antenna packageaccording to an embodiment of the invention, which can be implemented inthe wireless communications package structure of FIG. 10.

FIG. 12 schematically depicts an antenna package according to anembodiment of the invention in which ungrounded parasitic patch elementsare utilized for reducing surface waves to enhance the broadside antennaradiation characteristics.

FIG. 13 schematically depicts an antenna package according to anotherembodiment of the invention in which multiple patch antennas areutilized to provide polarization diversity for receive and transmitmodes of operation.

FIG. 14 schematically depicts an antenna package according to anotherembodiment of the invention in which multiple patch antennas areutilized to provide polarization diversity for receive and transmitmodes of operation.

FIG. 15 schematically depicts a stack structure of an antenna packageaccording to another embodiment of the invention, which can beimplemented in the wireless communications package structure of FIG. 10.

FIG. 16 schematically depicts an antenna package according to anembodiment of the invention, which is implemented based on the stackstructure of FIG. 15.

FIG. 17 schematically depicts an antenna package according to anotherembodiment of the invention, which is implemented based on the stackstructure of FIG. 15.

DETAILED DESCRIPTION

Embodiments of the invention will now be discussed in further detailwith regard to structures and methods for integrally packaging antennastructures with semiconductor RFIC chips to form compact integratedradio/wireless communications systems that operate in the millimeterwave frequency range with radiation in broadside and end-firedirections. It is to be understood that the various layers, structures,and regions shown in the accompanying drawings are not drawn to scale,and that one or more layers, structures, and regions of a type commonlyused in integrated antenna and chip packages may not be explicitly shownin a given drawing. This does not imply that the layers, structures andregions not explicitly shown are omitted from the actual integrated chippackages. Moreover, the same or similar reference numbers usedthroughout the drawings are used to denote the same or similar features,elements, or structures, and thus, a detailed explanation of the same orsimilar features, elements, or structures will not be repeated for eachof the drawings.

FIG. 1 schematically depicts a wireless communications package 10according to an embodiment of the invention. In general, the wirelesscommunications package 10 comprises an antenna-in-package 100 (or“antenna package”), an RFIC chip 130, and an application board 140. Theantenna package 100 comprises a first substrate 110 and a secondsubstrate 120. The first substrate 110 comprises a first antenna 112 andan antenna ground plane 114, which are formed on opposing sides of thefirst substrate 110. The second substrate 120 comprises a second antenna122 and other metallization patterns 124, 126 and 128 formed on asurface thereof, which include contact pads 126, electrical wiring, etc.An antenna feed line 116 is formed through the first and secondsubstrates 110 and 120 in electrical contact with the first antenna 112and the metallization pattern 126.

In one embodiment of the invention, the substrates 110 and 120 areformed of standard FR4 material with copper metallization, or othersuitable materials commonly used to construct a standard PCB (printedcircuit board), or other substrate materials that may be otherwiseselected to achieve a desired or optimal performance. The substrates 110and 120 can be formed with other materials having mechanical andelectrical properties that are similar to FR4, providing a relativelyrigid structure to support the antenna package 100 structure. Dependingon the application frequency and other factors related to the type ofplanar antenna structures used, the substrates 110 and 120 can each havea thickness in a range of about 1 mil to about 20 mils.

The RFIC chip 130 comprises a plurality of metallization patterns 132,134 and 136 formed on an active side thereof, which include contactpads, electrical wiring, etc. The RFIC chip 130 comprises RFIC circuitryand electronic components formed on the active side including, forexample, a receiver, a transmitter or a transceiver circuit, and otheractive or passive circuit elements that are commonly used to implementwireless RFIC chips. The metallization patterns 132, 134 and 136 of theRFIC chip 130 include, for example, ground pads, DC power supply pads,input/output pads, control signal pads, etc., which are formed as partof a BEOL (back end of line) wiring structure that is connected tointegrated circuit components of the RFIC chip 130, as is readilyunderstood by those of ordinary skill in the art. The RFIC chip 130 isflip-chip mounted to the second substrate 120 of the antenna package 100using controlled collapse chip connections (C4) 150, or other knowntechniques.

Moreover, the application board 140 comprises a plurality ofmetallization patterns 142 and 144 formed on a surface thereof, whichinclude contact pads, wiring, etc. The antenna package 100 is connectedto the application board 140 using ball grid array (BGA) connections152, or other known techniques. An under fill material 154 is used tostrengthen the C4 connections 150 and BGA connections 152.

In the embodiment of FIG. 1, the second substrate 120 serves as aninterface between the RFIC chip 130 and the application board 140 viathe C4 connections 150 and BGA connections 152. In particular, some BGAconnections 152 may be non-electrical connections that merely serve tobond the antenna package 100 to the application board 140. Similarly,some C4 connections 150 may be non-electrical connections that merelyserve to bond the RFIC chip 130 to the antenna package 100. For example,the BGA connection 152 between the metallization patterns 128 and 142can serve as a non-electrical, bonding connection.

Other BGA connections 152 and C4 connections 150 serve as bondingconnections, as well as electrical connections between the applicationboard 140 and the RFIC chip 130. For instance, in the embodiment of FIG.1, the C4 connection 150 and BGA connection 152 between themetallization patterns 134, 144, and 124 can form a power interconnectto supply DC power from the application board 140 to the RFIC chip 130,or otherwise provide an I/O interconnect to transmit I/O or controlsignals between the RFIC chip 130 and the application board 140, etc.Moreover, some C4 connections 150 serve as bonding connections, as wellas electrical connections between the RFIC chip 130 and the antennapackage 100. For instance, in the embodiment of FIG. 1, the C4connection 150 between the metallization patterns 126 and 136electrically connect an integrated circuit of the RFIC chip 130 with theantenna feed line 116, and can form a part of the antenna feed line.Moreover, the C4 connection 150 between the metallization pattern 132and the second antenna 122 metallization can form part of an antennafeed line that feeds the second antenna 122.

In the embodiment of FIG. 1, the wireless communications package 10provides broadside radiation R1 via the first antenna 112 (wherein theprimary radiation beam is perpendicular to the application board 140),as well as end-fire radiation R2 via the second antenna 122 (wherein theprimary radiation beam is parallel to the application board 140). Asshown in FIG. 1, the antenna package 100 is mounted to the applicationboard 140 so that an edge region of the antenna package 100 extends atsome distance, d, past an edge of the application board 140. Thismounting technique allows the second antenna 122 on the bottom of thesecond substrate 120 to be disposed away from other structures andcomponents of the wireless communications package 10, which prevents theradiation properties of the second antenna 122 from being adverselyaffected by the other structures and components of the wirelesscommunications package 10.

The wireless communications package 10 can support 60 GHzantenna-in-package solutions, for example, for either single antenna orphased-array applications for portable application such as electronictablets and smart phones. Indeed, for portable applications, thecombination of broadside and end-fire radiation improves wirelessperformance and reduces specific absorption rate (SAR), an importanthealth concern, especially with switchable antenna beams. While theantenna package 100 is shown as being formed with two separatesubstrates 110 and 120, an antenna package can be formed with onesubstrate. However, a single substrate design can make the antennapackage 100 larger in size, which may not be suitable for portableapplications where small size is desired.

Although the first and second antennas 112 and 122 are depictedgenerically in FIG. 1, the first and second antennas 112 and 122 can beimplemented using known antenna structures. For example, for broadsideradiation, the first antenna 112 can be a planar patch antenna or acavity antenna. For end-fire radiation, the second antenna 122 can be aYagi antenna, a tapered-slot antenna, a dipole antenna, a folded dipoleantenna, or a Vivaldi antenna, for example. Various antenna packagestructures with antennas providing broadside and end-fire radiation willnow be discussed in further detail with reference to FIGS. 2A/2B, 3A/3B,4, 5, 6A/6B. 7A/7B, 8A/8B, and 9.

For example, FIGS. 2A and 2B schematically depict an antenna package 200according to an embodiment of the invention, wherein FIG. 2A is aschematic top view of the antenna package 200, and FIG. 2B is aschematic side view of the antenna package 200. In general, the antennapackage 200 comprises a first substrate 210, a second substrate 220, andan RFIC chip 230 that is flip-chip mounted to a first surface 220A ofthe second substrate 220. The first substrate 210 and second substrate220 are bonded together using an adhesive layer 205 (or prepreg). Thefirst substrate 210 comprises a first patch antenna 211 and a secondpatch antenna 212 formed on a surface thereof. The second substrate 220comprises a first Yagi-Uda (Yagi) antenna 221 and a second Yagi antenna222 formed on the first surface 220A thereof. The first and second Yagiantennas 221 and 222 each comprise a respective driven element 221A and222A (e.g., folded dipole element) and respective parasitic elements221B and 222B (e.g. director elements). The ground plane 227 serves as areflector element for the first and second Yagi antennas 221 and 222. Inthe embodiment of FIGS. 2A/2B, the first and second patch antennas 211and 212 are used for transmitting and receiving broadside radiation,while the first and second Yagi antennas 221 and 222 are used forreceiving and transmitting end-fire radiation.

The antenna package 200 further comprises a plurality of feed lines thatconnect the RFIC chip 230 to the antennas 211, 212, 221, and 222. Inparticular, a first antenna feed line 213/223 feeds the first patchantenna 211, a second antenna feed line 214/224 feeds the second patchantenna 212, a third antenna feed line 225 feeds the first Yagi antenna221, and a fourth antenna feed line 226 feeds the second Yagi antenna222. A ground plane 227 is formed on second surface of the secondsubstrate 220 opposite the first on which the first and second Yagiantennas 221 and 222 are formed. In many 60 GHz applications, forexample, transmitting antennas use differential feed lines, whilereceiving antennas use single-ended feed lines.

In this regard, in one embodiment of the invention, the first patchantenna 211 operates as a transmitting antenna in the broadsidedirection, which is fed by a differential antenna feed line, while thesecond patch antenna 212 operates as a receiving antenna in thebroadside direction, which is fed by a single-ended antenna feed line.In particular, the first antenna feed line 213/223 comprises adifferential vertical probe portion 213, and a planar differential lineportion 223. The differential vertical probe portion 213 is connected tothe first patch antenna 211 and extends through the first and secondsubstrates 210 and 220. The planar different line portion 223 is formedon the surface 220A of the second substrate 220 and is connected to theRFIC chip 230.

The second antenna feed line 214/224 comprises a single vertical probeportion 214, and a single planar line portion 224. The single verticalprobe portion 214 is connected to the second patch antenna 212 andextends through the first and second substrates 210 and 220. The singleplanar line portion 224 is formed on the surface 220A of the secondsubstrate 220 and is connected to the RFIC chip 230. In otherembodiments of the invention, a single-ended patch antenna (with asingle-ended feed point) can be differentially fed by using a BALUN totransform the single-ended feed point to a differential feed, andthereby provide a differentially fed patch antenna having only one feedpoint attached to the patch antenna.

Furthermore, in one embodiment of the invention, the first Yagi antenna221 operates as a receiving antenna in the end-fire direction, which isfeed by a single-ended antenna feed line, while the second Yagi antenna222 operates as a transmitting antenna in the end-fire direction, whichis feed by a differential antenna feed line. In particular, the thirdantenna feed line 225 is a BALUN that is formed on the first surface220A of the second substrate 200 connecting the first Yagi antenna 221to the RFIC chip 230, wherein the BALUN transforms the naturaldifferential input of the first Yagi antenna 221 to a single-ended feed.Moreover, the fourth antenna feed line 226 is a planar balanceddifferential feed line that is formed on the surface 220A of the secondsubstrate 220 connecting the second Yagi antenna 222 to the RFIC chip230.

In one embodiment of the invention, the differential vertical probeportion 213 and the single vertical probe portion 214 of the antennafeed lines are metallized via holes that are formed in the first andsecond substrates 210 and 220 in vertical alignment with each other. Theground plane 227 formed on the second surface 220B of the secondsubstrate 220 comprises a plurality of etched openings 227A throughwhich the vertical probe portions 213 and 214 can pass and remainelectrically isolated from the ground plane 227. The ground plane 227operates as an antenna ground plane for the first and second patchantennas 211 and 212, and serves as a ground plane for the planarantenna feed lines 223, 224, 225 and 226 that are formed on the firstsurface 220A of the second substrate 220, and further serves as thereflector element of the first and second Yagi antennas 221 and 222. Theground plane 227 is formed on the entire area of the second surface 220Bof the second substrate 220 except for the area under the first andsecond Yagi antennas 221 and 222.

As in the generic embodiment shown in FIG. 1, the antenna package 200 ofFIGS. 2A/2B can be mounted to an application board using BGA connectionsbetween the first surface 220A of the second substrate 220 and theapplication board, with the portion of the antenna package 200 havingthe first and second Yagi antennas 221 and 222 extending past an edge ofthe application board. In such instance, as noted above, the first andsecond patch antennas 211 and 212 facing away from the application boardwould be used for transmitting and receiving broadside radiation, whilethe first and second Yagi antennas 221 and 222 (disposed past the edgeof the application board) would be used for receiving and transmittingend-fire radiation.

Further, in one embodiment of the invention, the first patch antenna 211and second Yagi antenna 222 (transmitting antennas) can be independentlyoperated to transmit radiation in only one of the broadside or end-firedirections, or in both directions at the same time. Moreover, the firstpatch antenna 211 and second Yagi antenna 222 can be operated as atwo-element phased array antenna to steer the transmitting radiationbeam in a given direction between the broadside and end-fire directions,using beam steering techniques well-known to those of ordinary skill inthe art.

In another embodiment of the invention, the broadside patch antennas 211and 212, for example, can both be transmitting antennas that areconfigured as a mini phased array antenna with beam steering control. Inyet another embodiment, one or more additional patch antennas can beformed on the first substrate 210 (in addition to the first and secondpatch antennas 211 and 212), where the additional patch antenna operatesas a receiving antenna, while the broadside transmitting patch antennas211 and 212 are configured as a phased array antenna. In anotherembodiment of the invention, the broadside patch antennas 211 and 212can be connected to a transceiver circuit and alternatively operated astransmitting and receiving antennas using a transceiver switch with atime-division multiplexing (TDM) scheme, as is understood by those ofordinary skill in the art.

FIGS. 3A and 3B schematically depict an antenna package 300 according toan embodiment of the invention, wherein FIG. 3A is a schematic top viewof the antenna package 300, and FIG. 3B is a schematic side view of theantenna package 300. The antenna package 300 is similar to the antennapackage 200 discussed above with reference to FIGS. 2A and 2B, exceptthat the first patch antenna 211 is fed with a single-ended antenna feedline 313/323 which comprises a single vertical probe portion 313, and asingle planar line portion 323. The single vertical probe portion 313 isconnected to the first patch antenna 211 and extends through the firstand second substrates 210 and 220. The single planar line portion 323 isformed on the surface 220A of the second substrate 220 and is connectedto the RFIC chip 230.

Furthermore, the antenna package 300 comprises a ground plane 327 havingetched portions 327A to electrically isolate the vertical probe portions214 and 313 of the antenna feed lines from the ground plane 327.Further, the ground plane 327 comprises an area 327B that ispatterned/etched to form a first tapered-slot antenna 321 and a secondtapered-slot antenna 322, with single ended feeds. In particular, firstand second L-shaped feed lines 325 and 326 are formed on the firstsurface 220A of the second substrate 220. The first L-shaped feed line325 couples electromagnetic energy to and from an input slot portion321A of the first tapered-slot antenna 321, and the second L-shaped feedline 326 couples electromagnetic energy to and from an input slotportion 322A of the second tapered-slot antenna 322. The first andsecond tapered-slot antennas 321 and 322 are used for transmitting orreceiving end-fire radiation. In other embodiments of the invention, thefirst L-shaped feed line 325 and/or the second L-shaped feed line 326can be connected to a BALUN as needed, if the first tapered-slot antenna321 and/or the second tapered-slot antenna 322 are connected to adifferential-feed transceiver in the RFIC chip 230.

FIG. 4 schematically depicts an antenna package 400 according to anotherembodiment of the invention. The antenna package 400 shown in FIG. 4 issimilar to the antenna package 300 discussed above with reference toFIGS. 3A and 3B, except that the antenna package 400 comprises a firstfolded dipole antenna 421 and a second folded dipole antenna 422 toprovide end-fire radiation. Moreover, a first differential feed line 425is formed on the surface 220A of the second substrate 220 to feed thefirst folded dipole antenna 421, and a second differential feed line 426is formed on the surface 220A of the second substrate 220 to feed thesecond folded dipole antenna 422. Furthermore, a ground plane 427 (shownin dashed outline form) on the opposing surface of the second substrate220 does not extend under the first and second folded dipole antennas421 and 422.

In another embodiment of the invention, the first and second foldeddipole antennas 421 and 422 can be replaced with regular dipoleantennas. However, a folded dipole antenna provides wider bandwidth andbetter impedance matching than regular dipole antenna. Indeed, since adifferential feed line with high impedance is typically used to feed adipole or a folded dipole antenna, it is not possible to match theimpedance of a dipole antenna to the impedance of the differential feedline without using other impedance matching circuit structures.

FIG. 5 schematically depicts an antenna package 500 according to anotherembodiment of the invention. The antenna package 500 shown in FIG. 5 issimilar to the antenna package 400 discussed above with reference toFIG. 4, except that the antenna package 500 comprises a first Vivaldiantenna 521 and a second Vivaldi antenna 522 to provide end-fireradiation. The planar Vivaldi antenna structure provides very widebandwidth, which is desired for certain applications.

FIGS. 6A and 6B schematically depict an antenna package 600 according toanother embodiment of the invention, wherein FIG. 6A is a schematic topview of the antenna package 600, and FIG. 6B is a schematic side view ofthe antenna package 600. In general, similar to previously discussedembodiments, the antenna package 600 comprises a first substrate 610, asecond substrate 620, and an RFIC chip 230 that is flip-chip mounted toa first surface 620A of the second substrate 620. The first substrate610 and second substrate 620 are bonded together using an adhesive layer605.

Moreover, similar to the embodiment discussed above in FIGS. 2A/2B, thesecond substrate 620 comprises a first Yagi antenna 221 and a secondYagi antenna 222 formed on the first surface 620A thereof, eachcomprising a respective driven element 221A and 222A (e.g., foldeddipole element) and respective parasitic elements 221B and 222B (e.g.director elements). A ground plane 640 serves as a reflector element forthe first and second Yagi antennas 221 and 222. The ground plane 640 isformed on a surface 610A of the first substrate 610, which is bonded tothe second substrate 620. The perimeter of the ground plane 640 isdepicted in FIG. 6A as a dashed line. The first and second Yagi antennas221 and 222 are fed by first and second differential feed lines 625 and626 formed on the first surface 620A of the second substrate 620. As inpreviously discussed embodiments, the first and second Yagi antennas 221and 222 are used for end-fire radiation.

The first substrate 610 comprises a first aperture-coupled cavityantenna 611 and a second aperture-coupled cavity antenna 612 formedwithin the first substrate 610, which are used for broadside radiation.The first and second aperture-coupled cavity antennas 611 and 612 areformed by respective portions of dielectric material 613 and 614 of thefirst substrate 610 surrounded by metallic sidewalls and bottom walls ofthe antennas 611 and 612. In particular, the metallic sidewalls of thefirst and second aperture-coupled cavity antennas 611 and 612 aredefined by a series of metalized via holes 615 which form rectangularvia cages (as specifically shown in FIG. 6A) surrounding the respectiveportions of dielectric material 613 and 614. The metallic bottom wallsof the first and second aperture-coupled cavity antennas 611 and 612 aredefined by portions of the ground plane 640 within the perimeter of therespective via cages. The metalized via holes 615 that define theantenna sidewalls are spaced apart (pitch) at a distance that is lessthan one quarter wavelength of the desired operating frequency.

The ground plane 640 comprises a first aperture 641 and a secondaperture 642, which serve as coupling slots to couple electromagneticenergy to and from the respective first and second aperture-coupledcavity antennas 611 and 612 from respective first and second antennafeed lines 623 and 624. The first and second antenna feed lines 623 and624 transmit RF energy between the RFIC chip 230 and the first andsecond aperture-coupled cavity antennas 611 and 612. In one embodiment,the first and second antenna feed lines 623 and 624 are L-shaped striplines that utilize the ground plane 640 as the transmission line groundplane.

The first and second aperture-coupled cavity antennas 611 and 612 arealso referred to as “filled-cavity” antennas. In general, the resonantfrequencies of the first and second aperture-coupled cavity antennas 611and 612 is a function of the length, width and depth of the antennasstructures (as defined by the metalized via holes 615 and ground plane640), as well as the dielectric constant of the portions of thedielectric material 613 and 614 forming the antennas 611 and 612. Intypical designs, cavity antennas have a wider bandwidth than patchantennas. In other embodiment, the broadside antenna radiators may beaperture-coupled patch antennas that replace the first and secondaperture-coupled cavity antennas 611 and 612 in the antenna package 600.

FIGS. 7A and 7B schematically depict an antenna package 700 according toanother embodiment of the invention, wherein FIG. 7A is a schematic topview of the antenna package 700, and FIG. 7B is a schematic side view ofthe antenna package 700. In general, the antenna package 700 shown inFIGS. 7A and 7B has the same or similar components as shown in theantenna packages 200, 300 and 600 as discussed above, so a detaileddiscussion thereof will not be repeated. The antenna package 700 differsfrom the above embodiments in that the antenna package 700 comprises afirst substrate 710 having metalized via holes 715, a patterned metallictop plane 750, and a patterned metallic backplane 760. The patternedmetallic top plane 750 comprises etched regions 750A that electricallyisolate the first and second patch antennas 211 and 212 from themetallic top plane 750. Moreover, the patterned metallic backplane 760comprises etched regions 760A that are aligned with the first and secondpatch antennas 211 and 212 to expose the antenna ground plane 227.

The antenna package 700 is designed to suppress or eliminate thecreation of surface waves, which is a common problem for patch antennas,especially in package structures. Surface waves not only reduce antennaefficiency and adversely affect antenna performance, but also causeantenna-in-package reliability issues, such as reduced performancedepending on the location on an application board. In this regard, themetalized via holes 715, the metallic top plane 750, and the metallicbackplane 760 form isolating cavities for the first and second patchantennas 211 and 212. In particular, as more specifically shown in FIG.7A, the metalized via holes 715 essentially provide metallic cavitywalls that form rectangular via cages which surround the first andsecond patch antennas 211 and 212. The metalized via holes 715electrically connect the metallic top and back planes 750 and 760,thereby forming cavities that suppress or eliminate surface waves. Foreffective surface wave suppression, the spacing S (as shown in FIGS. 7Aand 7B) between the metalized via holes 715 and the edges of the etchedregions 750A and 760A of the metallic top and back planes 750 and 760should be approximately ¼ wavelength of the operating frequency. In thisembodiment, the metallic backplane 760 and the ground plane 227 are notphysically connected in DC, but they are virtually connected at 60 GHzfrequencies due to a large capacitance between the two planes 760 and227.

FIGS. 8A and 8B schematically depict an antenna package 800 according toanother embodiment of the invention, wherein FIG. 8A is a schematic topview of the antenna package 800, and FIG. 8B is a schematic side view ofthe antenna package 800. In general, the antenna package 800 shown inFIGS. 8A and 8B has the same or similar components as shown in theantenna package embodiments as discussed above, so a detailed discussionthereof will not be repeated. The antenna package 800 differs from theabove embodiments in that the first and second patch antennas 211 and212 (broadside radiating antennas) are vertically disposed below RFICchip 230, as compared to the antenna package 200, 300, 400, and 500, forexample, wherein the first and second patch antennas 211 and 212 arevertically disposed away (i.e., offset) from edge of the RFIC chip 230.In this regard, the antenna package 800 can provide a more compactstructure.

FIG. 9 schematically depicts an antenna package 900 according to anotherembodiment of the invention. In particular, FIG. 9 is a schematic topview of an antenna package 900 comprising a single substrate 910 havingvarious planar components patterned on a first surface 910A thereof, anda ground plane 927 formed on an opposing surface thereof (wherein theperimeter of the ground plane 927 is depicted as a dashed outline).Similar to the antenna package 200 shown in FIGS. 2A/2B, the antennapackage 900 includes first and second Yagi antennas 221 and 222 andassociated antenna feed lines 225 and 226, to receive and transmitend-fire radiation.

In addition, to receive or transmit broadside radiation, the antennapackage 900 comprises first and second edge-fed patch antennas 911 and912, and associated antenna feed lines 923 and 924, formed on the firstsurface 910A of the single substrate 910. In addition, the antennapackage 900 comprises a plurality of BGA pads 925 and associated feedconnections 926 to connect to the RFIC chip 230. In this embodiment, theantenna package 900 would be mounted to an application board via BGAconnections to the BGA pads 925, with the portion of the first surface910A having the antennas. 911, 912, 221 and 22 extended past edges ofthe application board. If the requirement of the antenna package size isnot critical or no more than four antennas are required, the singlesubstrate antenna package 900 design of FIG. 9 can be used.

FIG. 10 schematically depicts a wireless communications package 1000according another embodiment of the invention. In general, the wirelesscommunications package 1000 comprises an antenna-in-package 1010 (or“antenna package”), an RFIC chip 1030, and an application board 1040.The antenna package 1010 comprises a first substrate 1012, a firstadhesive layer 1014, a second substrate 1016, a second adhesive layer1018, and a third substrate 1020. A first metallization layer M1 isformed on one surface of the first substrate 1012. A secondmetallization layer M2 is formed on a surface of the second substrate1016. A third metallization layer M3 is formed on one surface of thethird substrate 1020, and a fourth metallization layer is formed onanother surface of the third substrate 1020.

As further shown in FIG. 10, the application board 1040 comprises ametallization layer 1042 formed on one surface thereof, and a pluralityof metallic thermal vias 1044 that are formed through the applicationboard 1040. A layer of thermal interface material 1032 is utilized tothermally couple the non-active (backside) surface of the RFIC chip 1030to a region of the application board that is aligned to the plurality ofmetallic thermal vias 1044. The layer of thermal interface material 1032serves to transfer heat to the thermal vias 1044, wherein the thermalvias 1044 serve as a heat sink (or a portion thereof) to dissipate heatthat is generated by the RFIC chip 1030.

The antenna package 1010 is electrically and mechanically connected tothe application board 1040 using an array of BGA connections 1050 (orother similar techniques). The BGA connections 1050 are formed betweencorresponding contact pads and wiring patterns of the fourthmetallization layer M4 on the third substrate 1020, and contact pads andwiring patterns of the metallization layer 1042 on the application board1040.

The RFIC chip 1030 comprises a metallization pattern on an active (frontside) surface thereof, which includes, for example, ground pads, DCpower supply pads, input/output pads, control signal pads, associatedwiring, etc., that are formed as part of a BEOL (back end of line)wiring structure of the RFIC chip 1030. The RFIC chip 1030 iselectrically and mechanically connected to the antenna package 1010 byflip-chip mounting the front-side contacts of the RFIC chip 1030 tocorresponding contact pads of the metallization layer M4 on the thirdsubstrate 1020 of the antenna package 1010 using an array of solder ballcontrolled collapse chip connections (C4) 1060, or other knowntechniques. An under fill material 1062 is used to strengthen the C4connections 1060, and optionally the BGA connections 1050.

The embodiment of the wireless communications package 1000 of FIG. 10 issimilar to the embodiment of the wireless communication package 10 ofFIG. 1 in that the antenna package 1010 of FIG. 10 genericallyillustrates antenna structures 112 and 122 (and associated feed lines)transmitting and/or receiving broadside radiation R1 and end-fireradiation R2, respectively. Moreover, the RFIC chip 1030 comprises RFICcircuitry and electronic components formed on the active side including,for example, a receiver, a transmitter or a transceiver circuit, andother active or passive circuit elements that are commonly used toimplement wireless RFIC chips.

While the embodiment of FIG. 1 shows the antenna package 100 mounted tothe application board 140 so that an edge region of the antenna package100 (in which the end-fire radiating antenna 122 is disposed) extends atsome distance, d, past an edge of the application board 140, theembodiment of FIG. 10 shows that the antenna package 1010 is mounted tothe application board 1040 with no extended end portion. In thisembodiment, the antenna package 1010 can be fabricated with materialsand structural configurations (as will be discussed below with referenceto FIGS. 11 and 15, for example) which are effective to eliminate orotherwise significantly reduce any adverse effects that other structuresand components of the wireless communications package 1000 may have onthe radiation properties (e.g., efficiency, directivity, etc.) of theend-fire radiating antenna 122. Similar to the embodiment of FIG. 1, thewireless communications package 1000 can support 60 GHzantenna-in-package solutions, for example, for either single antenna orphased-array applications for portable application such as electronictablets and smart phones, wherein for portable applications, thecombination of broadside and end-fire radiation improves wirelessperformance and reduces specific absorption rate (SAR), an importanthealth concern, especially with switchable antenna beams.

FIG. 11 schematically depicts an antenna package according to anembodiment of the invention, which can be implemented in the wirelesscommunications package 1000 of FIG. 10. More specifically, FIG. 11 is across-sectional schematic view of a portion of an antenna package 1110having a stack of layers similar to the antenna package 1010 of FIG. 10.In particular, the antenna package 1110 comprises a first substrate1012, a first adhesive layer 1014, a second substrate 1016, a secondadhesive layer 1018, and a third substrate 1020. In addition, theantenna package 1110 comprises a first metallization layer M1 formed ona surface 1012A of the first substrate 1012, a second metallizationlayer M2 formed on a surface of the second substrate 1016, a thirdmetallization layer M3 formed on one surface of the third substrate1020, and a fourth metallization layer M4 formed on another surface1020A of the third substrate 1020.

In one embodiment of the invention, the first metallization layer M1comprises one or more planar antenna structures (e.g., patch antenna112) to receive or transmit signals in the broadside direction, as wellas one or more ungrounded parasitic elements 1150 that are configured toimprove broadside antenna radiation characteristics by eliminating orreducing the surface waves on the surface 1012A of the first substrate1012. Various alternative embodiments of antenna packages comprisingungrounded parasitic elements will be discussed below in further detailwith reference to FIGS. 12, 13, and 14, for example.

Furthermore, in one embodiment of the invention, the secondmetallization layer M2 comprises a power plane 1140 that is configuredto distribute DC power to the RFIC chip 1030 from the application board1040. More specifically, in one embodiment of the invention, the secondmetallization layer M2 is a dedicated or special purpose metallic layerthat comprises relatively large metallic power supply patches (asopposed to thin power supply lines or traces) to distribute DC powerthrough the antenna package 1110 from the application board 1040 to theRFIC chip 1030. The use of relatively large power supply patches (asopposed to thin power supply lines or traces) provides for a low lossdistribution of DC power, e.g., low resistive loss as well as reducingor eliminating loss through inductance that may otherwise occur using aDC power distribution network of narrow power supply lines or traces.

Moreover, in one embodiment of the invention, the third metallizationlayer M3 comprises a ground plane 1130 that serves multiple purposes.For example, the ground plane 1130 is configured to provide a groundplane for the planar antennas (e.g., patch antenna 112) formed on thefirst substrate 1012. The ground plane 1130 is also configured toprovide a ground connection between ground pads on the application board1040 and ground terminals of circuitry on the RFIC chip 1030. Moreover,the ground plane 1130 serves as a ground shield to isolate the RFIC chip1030 from RF energy that is transmitted/received by the broadsideantenna(s) 112. Moreover, the ground plane 1130 serves as a ground forthe planar transmission lines (e.g. microstrip lines) that are formed onthe surface 1020A of the third substrate 1020 to provide antenna feedlines for the broadside and end fire antenna(s).

As further shown in FIG. 11, the fourth metallization layer M4 comprisesa plurality of contact pads 1022, 1024, 1026 and 1028, which serve toelectrically and mechanically connect the antenna package 1110 to theRFIC chip 1030 and the application board 1040 as discussed above (FIG.10). For example, the contact pad 1022 is a ground contact that isconnected to the ground plane 1130 using a metalized via hole V1 that isformed through the third substrate 1020. The contact pad 1024 is anantenna feed line contact that is connected to the planar antenna 112using a metalized via hole V2 that is formed through the layers 1012,1014, 1016, 1018, and 1020. In this embodiment, the metalized via holeV2 comprises a portion of an antenna feed line. The contact pad 1026 isa power supply contact that is connected to the power plane 1140 using ametalized via hole V3 that is formed through the layers 1016, 1018, and1020. The contact pad 1028 may be a non-electrical contact that merelyserves to bond the antenna package 1110 to the RFIC chip 1030 or theapplication board 1040.

In one embodiment of the invention, the first, second and thirdsubstrates 1012, 1016, and 1020 can be formed of standard FR4 materialwith copper metallization, or other suitable materials commonly used toconstruct a standard PCB (printed circuit board), or other substratematerials that may be otherwise selected to achieve a desired or optimalperformance for the target operating frequency. For example, in oneembodiment of the invention, the first, second and third substrates1012, 1016, and 1020 can be implemented using commercially availablehigh-performance hydrocarbon ceramic laminates having mechanical andelectrical properties that are optimal for high frequency applications(e.g., 60 GHz or higher).

By way of specific example, the first, second and third substrates 1012,1016, and 1020 can be implemented using the RO4000® series ofhydrocarbon ceramic laminates manufactured by Rogers Corporation. Thehydrocarbon ceramic laminates are formed of low loss dielectric materialthat can be used in high operating frequency applications in whichconventional circuit board laminates cannot be effectively used.Moreover, these commercially available hydrocarbon ceramic laminates canbe easily fabricated into printed circuit boards using standard FR-4circuit board processing techniques, thereby providing a low costsolution for constructing high performance antennal packages (as opposedto using more expensive laminate materials and processes such asPTFE-based laminates for high-frequency applications). The RO4000®series of hydrocarbon ceramic laminates are formed of a rigid, thermosetlaminate material that has a thermal coefficient of expansion similar tothat of copper, which provides good dimensional stability, and whichprovides reliable plated through-hole quality.

In one embodiment of the invention, for a 60 GHz application, each ofthe first, second and third substrates 1012, 1016, and 1020 can befabricated using a hydrocarbon ceramic laminate with a thickness ofabout 4 mils (or less for higher operating frequencies). Moreover, theadhesive layers 1014 and 1018 can be formed of a thermoset epoxy prepregadhesive material that is suitable for the given application. Theadhesive layers 1014 and 1018 can have a thickness in a range ofapproximately 1-2 mils. The thickness of the various layers will varydepending on the operating frequency and other factors related to thetype of planar antenna structures used. For example, for higheroperating frequencies, the thickness of the layers 1012, 1014, 1016,1018, and 1020 will decrease. Moreover, in the embodiment of FIG. 11, asthe overall thickness of the antenna package 1110 decreases with higheroperating frequencies, the power plane 1140 and ground plane 1130metallization levels can be switched, wherein the ground plane 1130 isdisposed between the power plane 1140 and the first metallization layerM1.

Although the unground parasitic element 1150 and antenna 112 aredepicted generically in FIG. 11, these components can be implementedusing various structures and antenna frameworks, as will be now bediscussed in further detail with reference to FIGS. 12, 13 and 15. Forexample, FIG. 12 schematically depicts an antenna package according toan embodiment of the invention in which ungrounded parasitic patchelements are utilized for reducing surface waves to enhance thebroadside antenna radiation characteristics. More specifically, FIG. 12is a schematic plan view of an antenna package 1200 comprising a stackof layers (e.g., layer 1012, 1014, 1016, 1018, and 1020) similar to theembodiment of FIG. 11, wherein the RFIC chip 1030 is shown (in phantom)as being flip chip mounted to the bottom surface 1020A of the thirdsubstrate 1020.

The first substrate 1012 comprises a first patch antenna 1211 and asecond patch antenna 1212 formed on the upper surface 1012A thereof. Inaddition, a plurality of ungrounded parasitic patch elements 1250, 1251,1252, and 1253 are formed on the upper surface 1012A of the firstsubstrate 1012. Moreover, similar to the embodiment shown in FIG. 2A,the third substrate 1020 comprises a first Yagi antenna 1221 and asecond Yagi antenna 1222 formed on the bottom surface 1020A thereof. Thefirst and second Yagi antennas 1221 and 1222 each comprise a respectivedriven element 1221A and 1222A (e.g., folded dipole element) andrespective parasitic elements 1221B and 1222B (e.g. director elements).

The antenna package 1200 further comprises a plurality of feed linesthat connect the RFIC chip 1030 to the antennas 1211, 1212, 1221, and1222. In particular, a first antenna feed line 1213/1223 feeds the firstpatch antenna 1211, a second antenna feed line 1214/1224 feeds thesecond patch antenna 1212, a third antenna feed line 1225 feeds thefirst Yagi antenna 1221, and a fourth antenna feed line 1226 feeds thesecond Yagi antenna 1222. The outer boundary of the ground plane 1130(and application board metallization 1042 (see FIG. 10)) is depicted inFIG. 12 as a dashed rectangle.

As noted above, in many 60 GHz applications, for example, transmittingantennas use differential feed lines, while receiving antennas usesingle-ended feed lines. In this regard, in one embodiment of theinvention, the first patch antenna 1211 operates as a transmittingantenna in the broadside direction, which is fed by a differentialantenna feed line, while the second patch antenna 1212 operates as areceiving antenna in the broadside direction, which is fed by asingle-ended antenna feed line. In particular, the first antenna feedline 1213/1223 comprises differential vertical vias 1213 (e.g., platedvia holes), and a planar differential line 1223. The differentialvertical vias 1213 are connected to the first patch antenna 1211 andextend through the stack of layers 1012, 1014, 1016, 1018, and 1020. Theplanar differential line 1223 is formed on the bottom surface 1020A ofthe third substrate 1020 and is connected to the RFIC chip 1030.

The second antenna feed line 1214/1224 comprises a single vertical via1214, and a single-ended antenna feed line 1224. The single vertical via1214 is connected to the second patch antenna 1212 and extends throughthe stack of layers 1012, 1014, 1016, 1018, and 1020. The single-endedantenna feed line 1224 is formed on the bottom surface 1020A of thethird substrate 1020 and is connected to the RFIC chip 1030. In otherembodiments of the invention, a patch antenna (with a single-ended feedpoint) can be differentially fed by using a BALUN to transform thesingle-ended feed point to a differential feed, and thereby provide adifferentially fed patch antenna having only one feed point attached tothe patch antenna.

In another embodiment of the invention, as shown in FIG. 12, a circulararrangement of shielding vias 1216 can be formed around the singlevertical via 1214 to provide RF shielding. More specifically, thecircular arrangement of shielding vias 1216 can be formed in the thirdsubstrate 1020 surrounding the portion of the vertical via 1214 thatextends through the third substrate 1020, and connected to the groundplane 1130. The circular arrangement of shielding vias 1216 canoptionally be utilized, when necessary, to provide coaxial shielding ofthe vertical via 1124 from low frequency connections on the bottomsurface 1020A of the third substrate and the RFIC chip 1030.

Furthermore, in one embodiment of the invention, the first Yagi antenna1221 operates as a receiving antenna in the end-fire direction, which isfed by a single-ended antenna feed line, while the second Yagi antenna1222 operates as a transmitting antenna in the end-fire direction, whichis fed by a differential antenna feed line. In particular, the thirdantenna feed line 1225 comprises a BALUN that is formed on the bottomsurface 1020A of the third substrate 1020 connecting the first Yagiantenna 1221 to the RFIC chip 1030, wherein the BALUN transforms thenatural differential input of the first Yagi antenna 1221 to asingle-ended feed. Moreover, the fourth antenna feed line 1226 is aplanar balanced differential feed line that is formed on the bottomsurface 1020A of the third substrate 1020 connecting the second Yagiantenna 1222 to the RFIC chip 1030.

In one embodiment of the invention, the differential vertical vias 1213and the single vertical via 1214 of the antenna feed lines (and optionalshielding vias 1216) are copper-plated through holes that are formedthrough the stack of layers 1012, 1014, 1016, 1018, and 1020. The groundplane 1130 (M3 metallization layer) operates as an antenna ground planefor the first and second patch antennas 1211 and 1212, and serves as aground plane for the planar antenna feed lines 1223, 1224, 1225 and 1226that are formed on the bottom surface 1020A of the third substrate 1020,and further serves as the reflector element of the first and second Yagiantennas 1221 and 1222.

In the embodiment of FIG. 12, the ungrounded parasitic patch elements1250, 1251, 1252, and 1253 formed on the upper surface 1012A of thefirst substrate 1012 are configured to improve the broadside radiationcharacteristics of the patch antennas 1211 and 1212 by reducing surfacewaves. More specifically, FIG. 12 illustrates that the patch antennas1211 and 1212 are rectangular-shaped patches having a length L (betweencritical edges), wherein the center frequency of operation of each patchantenna 1211 and 1212 is determined by its length L. As is known in theart, a microstrip patch antenna will have a length L that is equal toone-half of a wavelength within the dielectric (substrate) medium. Thewidth of the rectangular shaped patch antennas 1211 and 1212 can bevaried to adjust the impedance of the patch antennas 1211 and 1212.

In the embodiment of FIG. 12, because of their rectangular shape (asopposed to a square shape), the patch antennas 1211 and 1212 areconfigured to radiate and capture signals that are linear-polarized inthe left-right direction of the drawing. In this regard, the ungroundedparasitic patch elements 1250 and 1251 are disposed on either side ofthe patch antenna 1212 (adjacent the critical edges thereof which definethe patch length L) to minimize or eliminate the dominant surface wavesthat flow along the surface 1012A of the first substrate 1012 in theleft-right direction. Similarly, the ungrounded parasitic patch elements1252 and 1253 are disposed on either side of the patch antenna 1211(adjacent the critical edges thereof which define the patch length L) tominimize or eliminate the dominant surface waves that flow along thesurface 1012A of the first substrate 1012 in the left-right direction.

In one embodiment, to reduce or eliminate the surface waves along thesurface 1012A of the first substrate 1012 in the left-right direction,the ungrounded parasitic patch elements 1250 and 1251 are designed witha length L that is equal to one-half the wavelength within thedielectric (substrate) medium, and are separated from the patch antenna1212 by a distance D. In one embodiment of the invention, the distance Dis at least equal to, or greater than, one-half the free spacewavelength. Similarly, the ungrounded parasitic patch elements 1252 and1253 are designed with a length L that is equal to one-half thewavelength within the dielectric (substrate) medium, and are separatedfrom the patch antenna 1211 by the distance D. By reducing oreliminating the surface waves, the ungrounded parasitic patch elements1250, 1251, 1252 and 1253 serve to increase the radiation efficiency andenhance the radiation beam shape of the patch antennas 1211 and 1212 inthe broadside direction.

As with the embodiment discussed above with reference to FIGS. 2A/2B,the first patch antenna 1211 and second Yagi antenna 1222 (transmittingantennas) can be independently operated to transmit radiation in onlyone of the broadside or end-fire directions, or in both directions atthe same time. Moreover, the first patch antenna 1211 and second Yagiantenna 1222 can be operated as a two-element phased array antenna tosteer the transmitting radiation beam in a given direction between thebroadside and end-fire directions, using beam steering techniqueswell-known to those of ordinary skill in the art. In receiving mode,depending on the circuitry configuration of the RFIC chip 1030, thereceiving antennas 1212 and 1221 can be selectively operated dependingon whether the received signal is stronger in the broadside or end-firedirection.

FIG. 13 schematically depicts an antenna package according to anotherembodiment of the invention in which multiple patch antennas areutilized to provide polarization diversity for receive and transmitmodes of operation. More specifically, FIG. 13 is a schematic plan viewof an antenna package 1300 which is similar to the antenna package 1200of FIG. 12, except that the first substrate 1012 comprises four patchantennas 1311-1, 1311-2, 1312-1 and 1312-2, and corresponding ungroundedparasitic patch elements 1350, 1351, 1352, 1353, 1354, 1355, 1356 and1357, which are all formed on the upper surface 1012A of the firstsubstrate 1012. For ease of illustration, the end-fire antennastructures are not shown in FIG. 13.

In the embodiment of FIG. 13, the patch antennas 1312-1 and 1312-2 are“receive” patch antennas that are fed by respective single-ended antennafeed lines 1324-1 and 1324-2. The receive patch antennas 1312-1 and1312-2 each have a length L equal to one-half the wavelength within thedielectric (substrate) medium. The receive patch antennas 1312-1 and1312-2 are oriented orthogonally to each other to capturelinear-polarized signal in different directions. In particular, thereceive patch antenna 1312-1 is oriented to capture linear-polarizedwaves in the up-down direction of the drawing, while the receive patchantenna 1312-2 is oriented to capture linear-polarized waves in theleft-right direction of the drawing. The ungrounded parasitic patchelements 1350 and 1351 are disposed adjacent to the critical edges ofthe receive patch antenna 1312-1 (which define its length L) to reduceor eliminate surface waves that are generated in the up-down directionof the drawing. The ungrounded parasitic patch elements 1352 and 1353are disposed adjacent to the critical edges of the receive patch antenna1312-2 (which define its length L) to reduce or eliminate surface wavesthat are generated in the left-right direction of the drawing.

Furthermore, the patch antennas 1311-1 and 1311-2 are “transmit” patchantennas that are fed by respective differential antenna feed lines1323-1 and 1323-2. The transmit patch antennas 1311-1 and 1311-2 eachhave a length L equal to one-half the wavelength within the dielectric(substrate) medium. The transmit patch antennas 1311-1 and 1311-2 areoriented orthogonally to each other to transmit linear-polarized wavesin different directions. In particular, the transmit patch antenna1311-1 is oriented to transmit linear-polarized waves in the up-downdirection of the drawing, while the transmit patch antenna 1311-2 isoriented to transmit linear-polarized waves in the left-right directionof the drawing. The ungrounded parasitic patch elements 1354 and 1355are disposed adjacent to the critical edges of the transmit patchantenna 1311-1 (which define its length L) to reduce or eliminatesurface waves that are generated in the up-down direction of thedrawing. The ungrounded parasitic patch elements 1356 and 1357 aredisposed adjacent to the critical edges of the transmit patch antenna1311-2 (which define its length L) to reduce or eliminate surface wavesthat are generated in the left-right direction of the drawing.

Similar to the embodiment of FIG. 12 discussed above, the ungroundedparasitic patch elements 1350, 1351, 1352, 1352, 1354, 1355, 1356 and1357 are designed with a length L that is equal to one-half thewavelength within the dielectric (substrate) medium, and are separatedfrom the respective patch antennas 1311-1, 1311-2, 1312-1, and 1312-2 bya distance (pitch) D, wherein the distance D is at least equal to, orgreater than, one-half the free space wavelength of the operatingfrequency.

The embodiment of FIG. 13 provides polarization diversity for receiveand transmit modes of operation in the broadside direction. In oneembodiment of the invention, for broadside transmission, one of thetransmit patch antennas 1311-1 or 1311-2 can be selected to transmit alinear polarized wave in a desired direction. Moreover, for broadsidereception, either one or both of the receive patch antennas 1312-1 and1312-2 can be selected to receive signals in one or bothlinear-polarized directions.

FIG. 14 schematically depicts an antenna package according to anotherembodiment of the invention in which multiple patch antennas areutilized to provide polarization diversity for receive and transmitmodes of operation. More specifically, FIG. 14 is a schematic plan viewof an antenna package 1400 which comprises a first patch antenna 1411, asecond patch antenna 1412, a first ungrounded parasitic ring element1450, and a second ungrounded parasitic ring element 1452, which are alldisposed on the upper surface 1012A of the first substrate 1012. Forease of illustration, the end-fire antenna structures are not shown inFIG. 14.

In the embodiment of FIG. 14, the first and second patch antennas 1411and 1412 are square-shaped patch antenna elements with equal lengthsides of length L, wherein L is equal to one-half the wavelength withinthe dielectric (substrate) medium. The first patch antenna 1411 is fedwith a differential feed line 1423-1 and a single-ended antenna feedline 1424-1. The second patch antenna 1412 is fed with a differentialfeed line 1423-2 and a single-ended antenna feed line 1424-2. In thisregard, each patch antenna 1411 and 1412 can be operated as either areceive antenna or a transmit antenna, while providing polarizationdiversity.

For example, the differential feed line 1423-1 enables the first patchantenna 1411 to transmit linear-polarized signals in a left-rightdirection, while the differential feed line 1423-2 enables the secondpatch antenna 1412 to transmit linear polarized signals in an up-downdirection. In a transmit mode of operation, one of the first and secondpatch antennas 1411 or 1412 can be differentially fed (selectively) totransmit signals in one of the linear-polarized directions (up-down orleft-right). Moreover, since the first and second patch antennas 1411and 1412 are square-shaped, the first and second patch antennas 1411 and1412 can receive signals that are linear-polarized in either of the twoorthogonal directions (up-down and left-right). In addition, thesquare-shaped first and second patch antennas 1411 and 1412 are capableof receiving circular-polarized signals.

As further shown in FIG. 14, the first ungrounded parasitic ring element1450 surrounds the first patch antenna 1411 and the second ungroundedparasitic ring element 1452 surrounds the second patch antenna 1412. Thefirst and second ungrounded parasitic ring elements 1450 and 1452 aresquare-shaped rings that are configured to reduce surface waves alongthe surface 1012A of the first substrate 1012 in both the up-down andleft-right directions. Similar to the ungrounded parasitic patchelements discussed above with reference to FIGS. 12 and 13, each side ofthe first and second ungrounded parasitic ring elements 1450 and 1452has a length of L, wherein L is equal to one-half the wavelength withinthe dielectric (substrate) medium. Moreover, as shown in FIG. 14, eachside of the first ungrounded parasitic ring element 1450 is separatedfrom the patch antenna 1411 by a distance (pitch) D, wherein thedistance D is at least equal to, or greater than, one-half the freespace wavelength of the operating frequency. The same distance (pitch) Dis applicable to the spacing between the second patch antenna 1412 andthe second ungrounded parasitic ring element 1452.

While the embodiment of FIG. 14 shows the use of ungrounded parasiticring elements 1450 and 1452, in circumstances wherein there is limitedarea, ungrounded parasitic patch elements can be used in place of one orboth of the ungrounded parasitic ring elements 1450 and 1452 to reduceor eliminate surface waves. For example, in one embodiment, a separateungrounded parasitic patch element can be disposed adjacent to eachcritical edge of the first and second patch antennas 1411 and 1412 usingtechniques as discussed above with reference to FIGS. 12 and 13, forexample.

FIG. 15 schematically depicts an antenna package according to anembodiment of the invention, which can be implemented in the wirelesscommunications package of FIG. 10. More specifically, FIG. 15 is across-sectional schematic view of a portion of an antenna package 1510having a stack of layers comprising a first substrate 1512, an adhesivelayer 1518, and a second substrate 1520. In addition, the antennapackage 1510 comprises a first metallization layer M1 formed on a uppersurface 1512A of the first substrate 1512, a second metallization layerM2 formed on a bottom surface of the first substrate 1512, a thirdmetallization layer M3 formed on an upper surface of the secondsubstrate 1520, and a fourth metallization layer M4 formed on bottomsurface 1520A of the second substrate 1520.

In one embodiment of the invention, the first metallization layer M1comprises one or more planar antenna structures (e.g., patch antenna112) for receiving or transmitting signals in the broadside radiation,as well as one or more grounded parasitic elements 1550 and 1552 thatare configured to improve broadside antenna radiation characteristics byeliminating or reducing the surface waves on the surface 1512A of thefirst substrate 1512. Various alternative embodiments of antennapackages comprising grounded parasitic elements will be discussed belowin further detail with reference to FIGS. 16 and 17, for example.

In addition, in the embodiment of FIG. 15, the first metallization layerM1 comprises one or more power supply patches 1540, which collectivelyprovide a power plane that is configured to distribute DC power to theRFIC chip 1030 from the application board 1040. The embodiment of FIG.15 is to be contrasted with the embodiment of FIG. 11 in which thesecond metallization layer M2 is configured as a dedicated power supplyplane. However, in the embodiment of FIG. 15, the second metallizationlayer M2 comprises a capacitively coupled ground plane 1532 which isconfigured to provide a ground connection for the grounded parasiticelements 1550, 1552 through capacitive coupling to a ground plane 1530provided by the third metallization layer M3. More specifically, asshown in FIG. 15, the grounded parasitic elements 1550 and 1552 areconnected to the capacitively coupled ground plane 1532 using metalizedvia holes V4. The capacitively coupled ground plane 1532 is AC coupledto the ground plane 1530 through the adhesive layer 1518. Thisconfiguration effectively provides a ground connection for the groundedparasitic elements 1550 and 1552 without having to form a partial viahole through the first substrate 1512 and the adhesive layer 1518 to theground plane 1530 (which would be problematic as discussed below).

Moreover, as discussed above, the ground plane 1530 serves multiplepurposes. For example, the ground plane 1530 (i) provides an antennaground plane for the planar antennas (e.g., patch antenna 112) formed onthe first substrate 1512, (ii) provides a ground connection betweenground pads on the application board 1040 and ground terminals ofcircuitry on the RFIC chip 1030, (iii) provides a ground shield toisolate the RFIC chip 1030 from RF energy that is transmitted/receivedby the broadside antenna(s) 112, and (iv) provides a ground for planartransmission lines (e.g. microstrip lines) that are formed on thesurface 1520A of the second substrate 1520 to provide antenna feed linesfor the broadside and end fire antenna(s).

As further shown in FIG. 15, the fourth metallization layer M4 comprisesa plurality of contact pads 1522, 1524, 1526 and 1528 that serve toelectrically and mechanically connect the antenna package 1510 to theRFIC chip 1030 and the application board 1040 as discussed above. Forexample, the contact pad 1522 is a power supply contact that isconnected to a power supply patch 1540 on the surface 1512A of the firstsubstrate 1512 using a metalized via hole V3 that is formed through thelayers 1512, 1518 and 1520. The contact pad 1524 is a ground contactthat is connected to the ground plane 1530 using a metalized via hole V1that is formed through the second substrate 1520. The contact pad 1526is an antenna feed line contact that is connected to the planar antenna112 using a metalized via hole V2 that is formed through the layers1512, 1518, and 1520 (wherein the metalized via hole V2 comprises aportion of an antenna feed line). The contact pad 1528 may be anon-electrical contact that merely serves to bond the antenna package1510 to the RFIC chip 1030 or the application board 1040.

In one embodiment of the invention, the antenna package 1510 can befabricated using materials and techniques that are the same or similarto those discussed above for the antenna package 1110 embodiment of FIG.11, for example. The stack structures shown in FIGS. 11 and 15 can befabricated using standard PCB fabrication technologies. With suchtechnologies, the metallized via holes shown in FIGS. 11 and 15 areformed by drilling via holes completely through one or moresubstrate/adhesive layers, and then performing a plating process toplate the via holes with copper, for example.

For example, in the embodiment of FIG. 11, package structure 1110 can befabricated as follows. The third substrate 1020 with the metalized viahole V1 and metallization layer M3 is formed, and then bonded to thesecond substrate 1016 using the adhesive layer 1018. Thereafter, one ormore via holes are drilled down through the second substrate 1016, theadhesive layer 1018, and the third substrate 1020, and the drilled holesare then plated to form the metalized via hole V3. The metallizationlayer M2 can be formed on the second substrate 1016 before or after theformation of metalized via hole V3. Then, the first substrate 1012 isbonded to the second substrate 1016 using the adhesive layer 1014.Thereafter, one or more via holes are drilled through the firstsubstrate 1012, the adhesive layer 1014, the second substrate 1016, theadhesive layer 1018, and the third substrate 1020, and the drilled holesare then plated to form the metalized via hole V2. Then, themetallization layers M1 and M4 can be formed on the upper and lowersurfaces of the stack structure.

In the embodiment of FIG. 11, each of the metalized via holes V1, V2 andV3 are formed by drilling completely through a partially or fullycompleted stack structure followed by a metal plating process. While theembodiment of FIG. 11 comprises ungrounded parasitic elements 1150 onthe first metallization layer M1, it would be problematic to fabricategrounded parasitic elements on the first metallization layer M1 in thestack structure of FIG. 11. This would require the formation of“partial” via holes by drilling holes partially through the stackstructure starting from the first substrate 1012 down to the groundplane 1130. With standard PCB fabrication processes, the formation ofpartial via holes is problematic and difficult. For example, it isdifficult to control the drilling process to stop at a precise point(e.g., at the ground plane 1130) within the stack structure, which canlead to failed connections. Moreover, in the embodiment of FIG. 11, theformation of partial vias to the ground plane 1130 could result indamage to the ground plane 1130.

In contrast, the stack structure 1510 shown in FIG. 15 enables groundconnections between the parasitic elements 1550 and 1552 and the groundplane 1530 without having to form partial vias. For example, packagestructure 1510 can be fabricated as follows. The first and secondsubstrates 1512 and 1520 are separately formed, wherein the firstsubstrate 1512 is initially formed with the capacitively coupled groundplane 1532 (metallization layer M3) and the metalized via holes V4, andwherein the second substrate 1520 is initially formed with the groundplane 1530 (metallization layer M3) and the metalized vial hole V1.Then, the first and second substrates 1512 and 1520 are bonded togetherusing the adhesive layer 1518. Thereafter, one or more via holes aredrilled through the first substrate 1512, the adhesive layer 1518, andthe second substrate 1520, and the drilled holes are then plated to formthe metalized via holes V2 and V3. Then, the metallization layers M1 andM4 can be formed on the upper and lower surfaces of the stack structure1510.

FIG. 16 schematically depicts an antenna package according to anembodiment of the invention, which is implemented based on the stackstructure of FIG. 15. More specifically, FIG. 16 is a schematic planview of an antenna package 1600 which comprises a broadside patchantenna configuration (1411 and 1412) and feed line configuration(1423-1, 1423-2, 1424-1, and 1424-2) formed on the upper surface 1512Aof the first substrate 1512, which are similar to the antenna/feed lineconfigurations of the embodiment of the antenna package 1400 of FIG. 14to provide polarization diversity.

The antenna package 1600 further comprises a first grounded parasiticring element 1650 surrounding the first patch antenna 1411, a secondgrounded parasitic ring element 1652 surrounding the second patchantenna 1412, and a plurality of power supply patches 1640 and 1642,which are all disposed on the upper surface 1512A of the first substrate1512. For ease of illustration, the end-fire antenna structures are notshown in FIG. 16.

Similar to the ungrounded parasitic ring elements 1450 and 1452 in FIG.14, the first and second grounded parasitic ring elements 1650 and 1652are square-shaped rings that are configured to reduce surface wavesalong the surface 1512A of the first substrate 1512 in both the up-downand left-right directions. Each of the first and second groundedparasitic ring elements 1650 and 1652 are connected to the capacitivelycoupled ground plane 1532 using an array of metalized via holes V4 (andthereby connected to the ground plane 1530 via AC coupling). Due to thegrounding, each side of the first and second grounded parasitic ringelements 1650 and 1652 has a length L′ equal to one-quarter thewavelength within the dielectric (substrate) medium. Similar to theungrounded parasitic ring elements 1450 and 1452 in FIG. 14, each sideof the first and second grounded ring elements 1650 and 1652 isseparated from the respective patch antenna 1411 and 1412 by a distance(pitch) D, wherein the distance D is at least equal to, or greater than,one-half the free space wavelength of the operating frequency.

While the embodiment of FIG. 16 shows the use of grounded parasitic ringelements 1650 and 1652, in circumstances where there is limited area,grounded parasitic patch elements can be used in place of one or more ofthe grounded parasitic ring elements 1650 and 1652 for one or more ofthe patch antennas, such as shown in the following embodiment of FIG.17.

FIG. 17 schematically depicts an antenna package according to anembodiment of the invention, which is implemented based on the stackstructure of FIG. 15. More specifically, FIG. 17 is a schematic planview of an antenna package 1700 which comprises a broadside patchantenna configuration (1311-1, 1311-2, 1312-1, 1312-2) and feed lineconfiguration (1323-1, 1323-2, 1324-1, 1324-2) formed on the uppersurface 1512A of the first substrate 1512, which is the same as theantenna/feed line configurations of the antenna package 1300 of FIG. 13to provide polarization diversity. The antenna package 1700 furthercomprises a plurality of grounded parasitic patch elements 1750, 1751,1752, 1753, 1754, 1755, 1756 and 1757, and a plurality of power supplypatches 1740 and 1742, which are all disposed on the upper surface 1512Aof the first substrate 1512. For ease of illustration, the end-fireantenna structures are not shown in FIG. 17.

The grounded parasitic patch elements 1750 and 1751 are disposedadjacent to the critical edges of the receive patch antenna 1312-1(which define its length L) to reduce or eliminate surface waves thatare generated in the up-down direction of the drawing. The groundedparasitic patch elements 1752 and 1753 are disposed adjacent to thecritical edges of the receive patch antenna 1312-2 (which define itslength L) to reduce or eliminate surface waves that are generated in theleft-right direction of the drawing. The grounded parasitic patchelements 1754 and 1755 are disposed adjacent to the critical edges ofthe transmit patch antenna 1311-1 (which define its length L) to reduceor eliminate surface waves that are generated in the up-down directionof the drawing. The grounded parasitic patch elements 1756 and 1757 aredisposed adjacent to the critical edges of the transmit patch antenna1311-2 (which define its length L) to reduce or eliminate surface wavesthat are generated in the left-right direction of the drawing.

Each of the grounded parasitic patch elements 1750, 1751, 1752, 1753,1754, 1755, 1756 and 1757 are connected to the capacitively coupledground plane 1532 using an array of metalized via holes V4 (and therebyconnected to the ground plane 1530 via AC coupling). Due to thegrounding, each of the grounded parasitic patch elements 1750, 1751,1752, 1753, 1754, 1755, 1756 and 1757 has a length L′ equal toone-quarter the wavelength within the dielectric (substrate) medium.Moreover, each of the grounded parasitic patch elements 1750, 1751,1752, 1753, 1754, 1755, 1756 and 1757 is separated from the respectivepatch antenna 1311-1, 1311-2, 1312-1, 1312-2 by a distance (pitch) D,wherein the distance D is at least equal to, or greater than, one-halfthe free space wavelength of the operating frequency.

While the embodiment of FIG. 17 shows the use of grounded parasiticpatch elements, in circumstances wherein there is enough area, groundedparasitic ring elements as shown in FIG. 16 can be used in place of thegrounded parasitic patch elements for one or more of the patch antennas1311-1, 1311-2, 1312-1, 1312-2 to reduce or eliminate surface waves.

Moreover, as shown in FIGS. 16 and 17, the power supply patches1640/1642 and 1740/1742 can occupy are relatively large area on thesurface 1512A of the first substrate 1512 without affecting antennaperformance, while at the same time providing a low loss, low inductancepower plane that enables the distribution of DC supply voltage from theapplication board to the RFIC chip.

Those of ordinary skill in the art will readily appreciate the variousadvantages associated with integrated chip/antenna package structuresaccording to embodiments of the invention. For instance, an antennapackage structure can be readily fabricated using known PCBmanufacturing and packaging techniques to fabricate and package antennastructures with semiconductor RFIC chips to form compact integratedradio/wireless communications systems for millimeter wave applicationswith radiations in the broadside and end-fire directions. Moreover,integrated chip packages according to embodiments of the inventionenable antennas to be integrally packaged with IC chips such astransceiver chips, which provide compact designs with very low lossbetween the transceiver and the antenna.

Moreover, various types of antenna designs can be implemented asdiscussed above to transmit and/or receive broadside and end-fireradiation. Although embodiment of antenna packages discussed hereindepict two or three substrates, antenna packages can be constructed withfour or more substrates, depending on the intended application.Moreover, although the embodiments discussed herein show the use of twoor four antennas for broadside and end-fire radiations, additionalantenna elements can be included to achieve increased antenna gain or toimplement phased array antenna structures.

It is to be further understood that the antenna package structuresillustrated herein can extended or varied depending on the application,e.g., antenna structure, I/O routing requirements, power and groundplane requirements, etc. Those of ordinary skill in the art readilyunderstand that the antenna performance parameters such as antennaradiation efficiency and bandwidth and operating resonant frequency willvary depending on the dielectric constant, loss tangent, and thicknessof the dielectric/insulating materials that form the substrate layers.Moreover, the size and structure of the various radiating elements ofthe antennas shown in drawings will determine the resonant frequency ofthe antenna, as is well understood to those of ordinary skill in theart.

Although embodiments have been described herein with reference to theaccompanying drawings for purposes of illustration, it is to beunderstood that the present invention is not limited to those preciseembodiments, and that various other changes and modifications may beaffected herein by one skilled in the art without departing from thescope of the invention.

We claim:
 1. A package structure, comprising: an antenna packagecomprising a plurality of stacked substrates comprising a firstsubstrate and a second substrate, and metallization layers including afirst metallization layer formed on a first surface of the firstsubstrate, and a second metallization layer formed on first surface ofthe second substrate, wherein the first metallization layer comprises afirst planar antenna and a grounded planar parasitic element disposedadjacent to the first planar antenna, and wherein the secondmetallization layer comprises a second planar antenna; an RFIC (radiofrequency integrated circuit) chip flip-chip bonded to the secondmetallization layer on the first surface of the second substrate of theantenna package; a first antenna feed line which comprises a metalizedvia hole that extends through the plurality of stacked substrates fromthe first surface of the second substrate to the first surface of thefirst substrate, wherein the first planar antenna is connected to theRFIC chip by the first antenna feed line; and a second antenna feed lineformed as part of the second metallization layer on the first surface ofthe second substrate, wherein the second antenna feed line extends alongthe first surface of the second substrate to connect the second planarantenna to the RFIC chip; wherein the first planar antenna is configuredto receive or transmit broadside signals and the second planar antennais configured to receive or transmit end-fire signals; and wherein thegrounded planar parasitic element is configured to reduce surface waveson the first surface of the first substrate.
 2. The package structure ofclaim 1, wherein the grounded planar parasitic element comprises aparasitic patch element disposed adjacent to a critical edge of thefirst planar antenna.
 3. The package structure of claim 1, wherein thegrounded planar parasitic element comprises a parasitic ring elementthat surrounds the first planar antenna.
 4. The package structure ofclaim 1, further comprising a third metallization layer disposed betweenthe first and the second metallization layers, wherein the thirdmetallization provides a dedicated ground plane.
 5. The packagestructure of claim 4, further comprising a fourth metallization layerdisposed between the third metallization layer and the firstmetallization layer, wherein the fourth metallization layer comprises acapacitively coupled ground plane, which is capacitively coupled to theground plane of the third metallization layer through an adhesive layer.6. The package structure of claim 5, wherein the fourth metallizationlayer is formed on a second surface of the first substrate opposite thefirst metallization layer formed on the first surface of the firstsubstrate, wherein the grounded planar parasitic element is connected tothe capacitively coupled ground plane using a plurality of metalized viaholes formed in the first substrate.
 7. The package structure of claim1, wherein the first planar antenna comprises a first square-shapedpatch antenna element, and wherein the first antenna feed line furthercomprises a single-ended feed line and a differential feed lineconnected to the first square-shaped patch antenna element, and whereinthe RFIC chip is configured to utilize the first square-shaped patchantenna element to receive or transmit signals in the broadsidedirection.
 8. The package structure of claim 7, wherein first planarantenna further comprises a second square-shaped patch antenna element,wherein the first antenna feed line further comprises a single-endedfeed line and a differential feed line connected to the secondsquare-shaped patch antenna element, and wherein the RFIC chip isconfigured to utilize the second square-shaped patch antenna element toreceive or transmit signals in the broadside direction.
 9. The packagestructure of claim 1, wherein the first planar antenna comprises a firstrectangular-shaped patch antenna element, a second rectangular-shapedpatch antenna element, a third rectangular-shaped patch antenna element,and a fourth rectangular-shaped patch antenna element; wherein the firstand second rectangular-shaped patch antenna elements are each fed byseparate single-ended antenna feed line portions of the first antennafeed line, and wherein the first and second rectangular-shaped patchantenna elements are oriented orthogonal to each other to receivebroadside signals in different linear-polarized directions; and whereinthe third and fourth rectangular-shaped patch antenna elements are eachfed by separate differential feed line portions of the first antennafeed line, wherein the third and fourth rectangular-shaped patch antennaelements are oriented orthogonal to each other to transmit broadsidesignals in different linear-polarized directions.
 10. The packagestructure of claim 1, wherein the first metallization layer comprisesone or more power supply patches to distribute a DC power supply voltageto the RFIC chip.
 11. A wireless communications system comprising thepackage structure of claim
 1. 12. A package structure, comprising: anantenna package comprising a plurality of stacked substrates comprisinga first substrate and a second substrate, and metallization layersincluding a first metallization layer formed on a first surface of thefirst substrate, and a second metallization layer formed on firstsurface of the second substrate, wherein the first metallization layercomprises a first planar antenna and a grounded planar parasitic elementdisposed adjacent to the first planar antenna, and wherein the secondmetallization layer comprises a second planar antenna; a first antennafeed line which comprises a metalized via hole that extends through theplurality of substrates from the first surface of the second substrateto the first surface of the first substrate; a second antenna feed lineformed as part of the second metallization layer on the first surface ofthe second substrate, wherein the second antenna feed line extends alongthe first surface of the second substrate and is coupled to the secondplanar antenna on the first surface of the second substrate; wherein thefirst planar antenna is configured to receive or transmit broadsidesignals and the second planar antenna is configured to receive ortransmit end-fire signals; and wherein the grounded planar parasiticelement is configured to reduce surface waves on the first surface ofthe first substrate.
 13. The package structure of claim 12, wherein thegrounded planar parasitic element comprises a parasitic patch elementdisposed adjacent to a critical edge of the first planar antenna. 14.The package structure of claim 12, wherein the grounded planar parasiticelement comprises a parasitic ring element that surrounds the firstplanar antenna.
 15. The package structure of claim 12, furthercomprising a third metallization layer disposed between the first andthe second metallization layers, wherein the third metallizationprovides a dedicated ground plane.
 16. The package structure of claim15, further comprising a fourth metallization layer disposed between thethird metallization layer and the first metallization layer, wherein thefourth metallization layer comprises a capacitively coupled groundplane, which is capacitively coupled to the ground plane of the thirdmetallization layer through an adhesive layer.
 17. The package structureof claim 16, wherein the fourth metallization layer is formed on asecond surface of the first substrate opposite the first metallizationlayer formed on the first surface of the first substrate, wherein thegrounded planar parasitic element is connected to the capacitivelycoupled ground plane using a plurality of metalized via holes formed inthe first substrate.
 18. The package structure of claim 12, wherein thefirst planar antenna comprises: a first square-shaped patch antennaelement, and wherein the first antenna feed line further comprises asingle-ended feed line and a differential feed line connected to thefirst square-shaped patch antenna element; and a second square-shapedpatch antenna element, wherein the first antenna feed line furthercomprises a single-ended feed line and a differential feed lineconnected to the second square-shaped patch antenna element.
 19. Thepackage structure of claim 12, wherein the first planar antennacomprises a first rectangular-shaped patch antenna element, a secondrectangular-shaped patch antenna element, a third rectangular-shapedpatch antenna element, and a fourth rectangular-shaped patch antennaelement; wherein the first and second rectangular-shaped patch antennaelements are each fed by separate single-ended antenna feed lineportions of the first antenna feed line, and wherein the first andsecond rectangular-shaped patch antenna elements are oriented orthogonalto each other to receive broadside signals in different linear-polarizeddirections; and wherein the third and fourth rectangular-shaped patchantenna elements are each fed by separate differential feed lineportions of the first antenna feed line, wherein the third and fourthrectangular-shaped patch antenna elements are oriented orthogonal toeach other to transmit broadside signals in different linear-polarizeddirections.
 20. The package structure of claim 12, wherein the firstmetallization layer comprises one or more power supply patches todistribute a DC power supply voltage.